Guilds that are benching players because their theoretical sim output is a few percent lower than someone else are probably not making the right choice.
HOW can you say that blizzard? Mythic Star Augur was a dps check until you guys decided to nerf it, and was the encounter that Method wiped most on, they wiped more on Augur than Gul'dan
did they bring classes that did less dps overall? no they gathered their highest st dps classes and tried to zerg the boss down again and again.
on a dps check fights you do wanna bring most dps as possible. who cares with farm raids.